Recently, submillimeter-wave technology in general and heterodyne techniques in particular have been highlighted as an important imaging capability for both, ground based and space applications. See I. Mehdi, B. Thomas, C. Lee, R. Lin, G. Chattopadhyay, J. Gill, N. Llombart, K. B. Cooper, P. H. Siegel, “Radiometer-on-a-chip: A path towards super-compact submm imaging arrays” SPIE Defense, Security and Sensing, April 2010, Orlando, Fla.; K. B. Cooper, R. J. Dengler, N. Llombart, T. Bryllert, G. Chattopadhyay, E. Schlecht, J. Gill, C. Lee, A. Skalare, I. Mehdi, P. H. Siegel, “Penetrating 3D Imaging at 4 and 25 Meter Range Using a Submillimeter-Wave Radar,” IEEE Trans. MTT., vol. 56, pp. 2771-2778, December 2008. Most heterodyne systems currently used provide sufficient science data in spite of being single pixel. However, recent applications in the submillimeter-wave range would greatly benefit from having large format heterodyne arrays, or namely terahertz cameras. For example, the imaging radar system presented in the second document cited above could speed up its acquisition time by having a focal plane array capable to image several pixels simultaneously.
A concept based on stacking multiple silicon layers has been proposed in the first document cited above. Such an assembly is expected to allow one to integrate an array of submillimeter-wave Schottky diode mixers and multipliers with MMIC amplifiers on the same wafer stack. However, in order to couple the RF signal, antenna technology that is consistent with silicon micro-fabrication is needed.
There is a need for improved methods of fabricating antennas operating at terahertz frequencies.